Shuffle lists and arrays, including primitive arrays.

See attached code.

edit]
shuffle() methods

// Example
shuffle(myArray);
shuffle(myArray, myRandomSeed);

marking as a possible enhancement. for what it's worth, i currently lean
away from adding more array methods, since even the original methods that
are in there are less useful nowadays than they were during the Java 1.1
time when the API was designed. Arrays.xxxx() can handle a lot of the work,
as can the Collections classes in different forms, so we'd be more likely
to break this out as a separate library, along with other more advanced
data handling methods.

for instance, we're thinking about a set of classes for data structures
like lists of ints or String objects, for which we'd add methods like this,
rather than building out PApplet further.